Sensory Nervous System and Photoreception

A set of vocabulary flashcards covering key concepts from the lecture on the sensory nervous system, including mechanisms of sensory reception and types of photoreception.

Sensory Neurons

Neurons that transmit information from sensory receptors to the central nervous system (CNS).

Free-nerve endings

Dendrites in afferent neurons that serve as sensory receptors, often associated with touch and pressure.

Photoreceptors

Specialized sensory cells that detect light; includes rods and cones in vertebrates.

Action Potential

A rapid change in voltage across a cellular membrane, allowing for the transmission of nerve impulses.

Mechanoreception

The sensory process of detecting mechanical stimuli such as touch, pressure, and sound.

Chemoreception

The detection of chemical stimuli in the environment, involved in the senses of taste and smell.

Thermoreception

The sensory detection of heat changes in the environment.

Electroreception

The ability to detect electric fields, particularly used by certain fish and amphibians.

Ocellus

A simple type of eye spot found in many invertebrates that can detect light intensity.

Compound Eyes

Eyes made up of multiple visual units (ommatidia) that allow for a broad range of vision in some invertebrates.

Camera Eyes

Complex eyes that can focus light using a lens, found in cephalopods and vertebrates.

Phototransduction

The process by which photoreceptors convert light into electrical signals.

Rods

Photoreceptors that are sensitive to low light and are responsible for vision in dim conditions.

Cones

Photoreceptors that detect color and function best in bright light conditions.

Glutamate

A neurotransmitter released by photoreceptors that plays a role in transmitting visual signals.

Sensory Adaptation

The reduced sensitivity to a constant stimulus over time.

Perception

The conscious awareness and interpretation of sensory information.

Neurotransmitter

Chemical messengers that transmit signals across synapses in the nervous system.